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"' ~ ~ • IIIIIIIIIIIIIIIIIII <br />STATE OF COLOR~UU <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1313 Sherman Sl., Room 215 <br />Denver, Colorado 80203 D I v 15 l o N O F <br />Phone: (3031 866-3567 MINERAL S <br />FAX: (303)832-8106 & <br />August 1, 2001 G E O L O G Y <br />RECLAMATION <br />MININ G•SAF ETY <br />Mr. Tim Krocesky <br />ACA Products, Inc. sill oven: <br />P.O. BOX 1887 Governor <br />Buena Vista, CO 81211 Greg E. Walther <br />Eaecutrve D~recloi <br />Michael B. Long <br />RE: Proposed Conditions of Approval, Trout Creek Pit 112c Application, Di~i:.on Dire~l~r <br />File No, M-2001.035 <br />Dear Mc Krocesky: <br />The Division has reviewed your responses to our adequacy review. The responses appropriately clarified your <br />application. However, we believe that it will be necessary to condition approval of your application. Please <br />review the following conditions and either let me know, in writing, tY(at you agree with [hem or that you propose <br />changes [o them. <br />Conditions No. I-Quarry High wall Stability <br />The quarry cut slopes will be in accordance with the adequacy response recommendations of R. J. Irish <br />in his report "Rock Cut Slope Stability Assessment, Planned Rock Quarry, Trout Creek Valley, Chaffee <br />County Colorado, Job No. 559". The cut slopes will be benched with 10 feet wide steps spaced about <br />20 fee[ apart in elevation and with risers drill-and-blast excavated to .25h:1v (76° slopes). The risers of <br />[he cut-slope will be dressed by barring down loose rock. The benches will be sloped to their [erminis <br />[o limit seepage into the jointed rock. A drainage ditch will be excavated immediately up slope of the <br />quarry to diver[ surface water runoff around the quarry. <br />Conditions No. 2-Offsite Damage and Dane Sajety (Trout Creek RCC DAM) <br />ACA Products will prepare industry standard blast reports for each blast in the quarry and, copies will <br />be submitted to the Division with each annual report. <br />A maximum charge weight of 42 lbs. per delay will not be exceeded without Division approval. Nine <br />millisecond delays will be used. The delay time will not be lessened without Division approval. <br />Each blast in the quarry will be monitored at the dam. A seismograph will be placed on bedrock a[ the <br />base of the dam. Blast frequency and peak particle velocity will be measured for each blast. Blast <br />frequencies will be limited to no less than 30 Hz. Peak particle velocity will not exceed 2 ips. The dam <br />seismograph monitoring data will be kept by the operator and made available [o the Division upon <br />request. <br />